The present invention relates to a method for removing the skin from a sausage and comprises the steps that an end portion of the sausage is cut off, that the skin is grasped by gripping means, that an incision is made in the sausage by a knife, that the gripping means and the sausage undergo a relative displacement in the longitudinal direction of the sausage and that the skin is pulled off in the longitudinal direction.
The present invention also relates to an apparatus for removing the skin from a sausage.
Patent specification SE 433 032 discloses a machine for removing skin from sausages which are interconnected to one another in a string. First, the sausages pass through a steam pipe to loosen the skin. Thereafter, the sausages are led up to a pair of feeder rollers in order subsequently to be cut from above by a knife blade edge. The skin is pulled off in that the sausages pass over a perforated suction roller or a vacuum wheel.
One of the drawbacks inherent in this apparatus is that the skin of the sausage, and thereby the subjacent surface, is heated to a relatively elevated temperature, which is not always desirable, among other things for reasons of shelf life. Another drawback is that a perforated suction roller is operationally unreliable since the perforations may readily become blocked by skin slivers or parts from the sausages. Furthermore, it would probably be difficult to clean the suction roller without the machine having to be partly dismantled. Finally, the method is likely to be difficult to employ for sausages which are not connected into a string.
EP 0 721 738 discloses an apparatus and a method for removing the skin from sausages and the like. Initially, the skin is severed in the end portion. A gripping device is moved in inside the edge of the skin and clamps this fast against a frame. Thereafter, the skinning unit, on which the gripping device and the frame are disposed, is moved towards the opposite end of the sausage, the skin being pulled off axially. The risk that the skin becomes folded or otherwise crumpled together is quite large, in particular when long sausages are involved. As a result, there is a quite serious risk of operational stoppage.
EP 0 732 054 discloses a method which is based on the principle that a sausage is provided with two curved incisions along each respective side of the sausage. Thereafter, the upper half of the sausage skin is pulled off, followed by the lower half. The two halves are connected together in the one end of the sausage, but the risk would appear to be quite large that the skin breaks or ruptures in the connection between the upper and the lower half, with consequential operational stoppage.
EP 0 509 477 shows how the skin may be removed from a sausage in that a knife cuts a longitudinal incision on the upper side of the sausage. The skin is grasped on each respective side of the incision with the aid of two suctions strips or beads. The suction strips are disposed on two arms which are pivoted outwards and thereby entrain the skin with them. The drawbacks inherent in a construction according to this Patent Specification are that the use of suction devices so close to the incision entails risks that only a part of the skin will be pulled off, and/or that the suction devices fasten in the sausage inside the incision.
The present invention has for its object to formulate the method intimated by way of introduction such that it may, with great operational reliability and rapidity, be employed for removing the skin from a sausage regardless of the appearance of the end portion of the sausage and regardless of whether there may be metal parts or the like disposed at the end portion of the sausage. Furthermore, the outside of the skin and any matter which has been in contact with it may not come into contact with the skinned sausage.
The present invention further has for its object to realize an apparatus for removing the skin from a sausage. Thus, the present invention relates to an apparatus which is easy to operate, which is extremely reliable in operation, which is flexible and which may therefore readily be adapted to different types and sizes of sausages, regardless of the appearance of the skin at the end of the sausage. Furthermore, the outside of the skin and any matter which has been in contact with it may not come into contact with the skinned sausage.
The objects forming the basis of the present invention will be attained in respect of the method if this is characterized in that the gripping means grasp the skin in diametrically opposed positions, and that the knife cuts the skin in the longitudinal direction of the sausage.
The objects forming the basis of the present invention will be attained in respect of the apparatus if this is characterized in that the gripping means are disposed on either side of the sausage, and that the knife is disposed below the sausage.
Further advantages will be attained according to the present invention if the method is given one or more of the characterizing features as set forth in appended subclaims 2 to 4 and if the apparatus is given one or more of the characterizing features as set forth in appended subclaims 6 to 9.